1. Field of the Invention
The invention relates to the evacuation of liquids and air from the pleural cavity in mammals. In particular, this invention relates to a chest tube and method for rapidly and accurately setting the chest tube in a patient in a medical emergency or trauma setting such that the tube performance is not impeded when inserted.
2. Background of the Invention
Thousands of cannulas or trocar catheters are inserted each year in patients suffering chest trauma brought on by incidents such as auto accidents, punctures and lung disease. These devices are used to evacuate air and liquids from the patient's pleural cavity, defined as that area of the human body between the neck and the diaphragm, partially encased by the ribs and containing the lungs. As is often the case in these situations, evacuation of materials is required immediately upon receiving a patient for treatment during an emergency and may be required for an extended period of time, for example during a patient's admittance to a hospital for treatment. To accomplish this, a practitioner experienced in setting chest tubes makes the necessary percutaneous penetration at an appropriate location on the patient's body and then inserts a flexible tube that contains small perforations or holes for receiving the material built up inside the patient's body. The material is then removed from the patient and discarded or otherwise processed. The chest tube is secured in place using a variety of methods common in the art including, but not limited to, adhesive tape, friction, suture with tether or tie lines.
A historical synopsis of the use of suction catheters, such as chest tubes, in general medical practice is disclosed in U.S. Pat. No. 4,738,666. As disclosed in that reference, the potential risk of infection from using chest tubes is outweighed by its benefits. However, passing a chest tube into a trauma patient's body so that the perforations at the distal end of the device are not partially blocked by a thoracic positioning between the lobes of a lung or having been placed between the chest wall and muscles, remains a challenge even to experienced emergency practitioners because it is a blind procedure. A misplaced chest tube results in a poorly functional or nonfunctioning tube due to partial blockage of the tube and a corresponding increase in hospitalization time and pain. Consequently, an improperly set chest tube reduces the medical benefits of the tube, possibly to the point where the risks are greater than the benefits of its use.
One method that has been frequently used to increase the efficiency of cannula and catheter tubes is to employ balloons. For example, prior to the conception of the present invention, dilation balloons attached to flexible tube cannulae have been employed for improving the efficiency of evacuation of fluids and solids. An apparatus for evacuating the stomach, as disclosed in U.S. Pat. No. 3,905,361, includes an elongated flexible tube with a perforated distal end for receiving stomach contents under vacuum, and an inflatable cuff balloon around the flexible tube for blocking the esophageal opening of the stomach to improve the vacuum. Similarly, an apparatus for assisting breathing, as disclosed in U.S. Pat. No. 3,788,326, includes a triple lumen flexible perforated catheter for use in a tracheal lumen to evacuate and supply air to the lungs, and an inflatable cuff balloon for positioning the tube in the trachea and increasing air flow through the tube.
In addition to the above uses, balloon catheters have been used in devices for blocking a blood vessel incision while an incision plug is set. Balloons have also been used extensively to extend or reposition a membrane within the patient's body. For example, in balloon angioplasty a double lumen apparatus containing an inflation lumen and an insertion lumen is inserted into a blood vessel and threaded forward to the location of a stenosis (restriction) where the balloon at the distal end of the device is inflated, forcing the blockage open. Often, the placement of a stent is accomplished at the same time to hold the vessel open. The balloon and stent are accurately placed because the operator can see the vessel and balloon using a special imaging system.
In still another use of balloons, a patient's heart atrial pressure has been measured by passing a nasal-gastric tube into the esophagus using a double lumen catheter with a dilation balloon and positioned adjacent to the left atrium of the patient's heart where the balloon is inflated to a set volume. The positioning of the balloon and catheter near the heart is accomplished either using an imaging system, an esophageal stethoscope or through trial and error by an experienced practitioner.
In still another use, a balloon catheter in which the balloon is employed at the distal end of a device is used to temporarily stop blood flow in a blood vessel. While the balloon is inflated, an optical fiber may be passed through the catheter to treat a lession or thrombi in the vessel with laser light, or an imaging fiber may be inserted to inspect the area of the lumen near the balloon where the blood flow has stopped.
While various configurations of the above balloon catheter/cannula devices have been used in the prior art, including devices with multiple lumens and multiple balloons, each of which may be inflated with air or liquids pumped from the proximate end of the device, and placed with assistance of imaging systems, none of the above devices or methods of using balloons have been employed with a chest tube to accurately set the chest tube inside a patient's thoracic region or other cavity to increase the effectiveness of evacuation.
What is needed, therefore, is an apparatus for the insertion of a chest tube in a proper position such that once it is inserted the tube is not partially blocked and a maximum volumetric flow rate is achieved. This can be accomplished, as in the present invention, using a dilation balloon or cuff attached to the chest tube to accurately position the tube inside the patient's thoracic cavity (or other cavity) and prevent it from resting on the inner chest wall or other membrane.